Apple 1 Replica Bootup/Display Problem.

6 posts / 0 new
Last post
Offline
Last seen: 9 hours 58 min ago
Joined: Nov 13 2018 - 16:32
Posts: 3
Apple 1 Replica Bootup/Display Problem.

Hi All,

Ive been trying to get my Apple 1 replica up and running. But i'm abit unsure how to fix this issue with my apple,

the screen turns on and displays dashes but there is no sign of any cpu bootup or any prompt.

When i press CLEAR it clears the screen but then goes back to the dashes again. Also RESET does nothing.

Thanks for your time.

Offline
Last seen: 17 hours 56 min ago
Joined: Oct 9 2011 - 12:54
Posts: 1139
First of all, I see a few

First of all, I see a few things going on here, before we can proceed in troubleshooting...

 

First, I hope you are going to put a heat sink on the LM323K....

 

Second, your "boot up" screen is "wrong.  I think you most likely have a bad 2504V shift register.

 

As for the reset "bouncing", do you have access to a logic analyzer or capturing oscilloscope?  I would eliminate that it is a mechaanical problem with the reset signal from the keyboard "bouncing".  While it looks like it's a leaf type keyboard you have there, it still could have issues.  If you had a datanetics, it would be an 80% change it was a reset switch.  Next I would check the wiriing and your cable.  Make sure it has a solid connection not intermittent.  Also grab a maginifing glass so you can look over the back of your board for poor solder joints.  

 

Once you have done the above post back and we can do some deeper troubleshooting.

 

Cheers,

Corey

 

Offline
Last seen: 9 hours 58 min ago
Joined: Nov 13 2018 - 16:32
Posts: 3
Update

Just abit of an update.

I've ordered new 2504v's, also i have the heatsink for the lm323k but im waiting for the mounting kit to arrive.

I will post an update when the parts arrive.

 

Thanks For The Help.

Offline
Last seen: 3 days 4 hours ago
Joined: Dec 1 2018 - 11:58
Posts: 1
Same thing here, I could get

Same thing here, I could get the normal "_@" flashing screen but when I press reset, it gave the same screen full of stationery "-" signs. The keyboard adapter connections are correct. It just cannot be reset even though the 6502 pin 40 voltage is pulled low during reset press.

Offline
Last seen: 17 hours 56 min ago
Joined: Oct 9 2011 - 12:54
Posts: 1139
@spectra208,   any progress

@spectra208,   any progress on what I mentioned?

 

@appehpman, please start a separate thread describing your issue and a picture of your board and setup. This will help us not mix spectra’s and your issues which may not be related.   Also double check your solder connections on the reverse side and that all chips are seated correctly without any bend under pins.  Then we can help you troubleshoot your issue. 

 

Cheers,

Corey

Offline
Last seen: 9 hours 58 min ago
Joined: Nov 13 2018 - 16:32
Posts: 3
Progress

@Cory986,

I have replaced all of the 2504v's and nothing changed, but i have noticed the 2519b is not working.

I am now waiting for another 2519b to arrive.

 

Thanks.

Log in or register to post comments